Online-only: Researchers identify new risks for sudden infant death syndrome

Thanks to a widespread campaign telling parents and caregivers to place babies on their backs to sleep, the rate of sudden infant death syndrome has dropped dramatically in the United States. But despite the progress, the syndrome remains the leading cause of death in children ages 1 month to 1 year. Some of those deaths may be due to newly identified risks, a recent study finds.

Since the launch of the Back to Sleep campaign in 1994, sudden infant death syndrome, or SIDS, has declined by more than 50 percent in the United States, according to federal statistics. Sleeping in a prone position, or face down, remains the No. 1 risk factor for SIDS, but the study points to additional risks that are often overlooked, including sleeping on adult mattresses, sharing beds with others, smoking during pregnancy and being born prematurely.

Published online March 26 in the journal Pediatrics, the study looked at SIDS deaths in San Diego from 1991 to 2008 and found that the percentage of infants who died of SIDS after being placed to sleep in the face-down position decreased from 84 percent to 48.5 percent. But the number of SIDS infants who were sharing beds with others at the time of death increased from 19.2 percent to nearly 38 percent, especially among infants younger than 2 months, and the number of babies who died in an adult bed increased from 23.4 percent to 45.4 percent.

“The overall SIDS rate has plateaued, and SIDS remains the leading cause of post-neonatal infant mortality in the United States today,” the study authors noted.

Understanding the precise risk factors for SIDS is critical to designing timely risk-reduction messages, said the authors, noting that though “prone sleep remains the most significant risk factor for SIDS, we found that sleeping on adult mattresses and bed-sharing, especially among younger infants, have emerged as additional prominent risks.”

The study is one of the first to address risk factors in SIDS infants in the United States before and after the initiation of the Back to Sleep campaign, which began in 1994 as a way to educate parents, caregivers and health care providers about ways to reduce the risk for SIDS. The campaign, named for its recommendation to place healthy babies on their backs to sleep, has been successful in promoting infant back sleeping and other risk-reduction strategies to parents, family members, child care providers, health professionals and all other caregivers of infants. The campaign is led by federal and nonprofit organizations.

“If caretakers are unable to meet all ideal sleep conditions, this study suggests that meeting as many as possible will still be beneficial,” the study authors concluded.